Aspergillus ustus

Macroscopic morphology

Colonies on potato dextrose agar at 25°C are white to yellow to drab gray to brown, but never green. Gray is the most common color. Reverse yellow to brown with a yellow diffusing pigment. Exudate, when present, is clear to yellow to purplish-brown. Rapid growth. Texture is woolly to cottony to somewhat granular.

Microscopic morphology

Hyphae are septate and hyaline. Conidial heads are radiate to loosely columnar and biseriate. Conidiophores 30-350 µm, smooth-walled, and brown. Vesicles are globose to subglobose, 7-16 µm in diameter. Metulae and phialides cover the upper portion of the vesicle. Conidia are globose, 3-4.5 µm, with very rough walls. Hülle cells, irregular to elongate in shape, should be searched for, and may be light dependent[531, 1215, 1875, 2202].

Special notes

This species has been reported as an agent of fungal endocarditis on a prosthetic valve[387], primary cutaneous disease in immunosuppressed patients [819], [1612], [1919], [2167], and invasive disseminated disease,[148] , [1105], [2317], and[2394]. Strains have been differentiated by random amplification of polymorphic DNA [1876].